ISLAMABAD -- A suicide bomb attack on a Shi'ite procession in Rawalpindi, near Pakistan's capital, has killed 23 people and wounded 60 others.

The Pakistani Taliban claimed responsibility for that and another attack, both of which took place on November 21.

The killings cast a pall over an international meeting in the capital this week, and appear aimed at fomenting sectarian animosity between Sunnis and Shi'a.

But horrified local residents and rescuers were responding with a common front against militants seeking to weaken the central government's control of the country.

“I was on way to [the Shi'ite gathering] when the blast took place," resident Raja Muhammad Saeed told RFE/RL's Radio Mashaal. "At the scene [of the blast], only five to 10 government officials who later left the area were present. Mostly the rescue work was being carried out by Sunnis, and they are still helping in the rescue work."

The Pakistani Army is headquartered in Rawalpindi, the country's fourth-largest city.

Rescue workers and ambulances are seen at the site of a second bomb blast in Karachi overnight on November 21-22.

Earlier in the day, two bombs detonated within minutes of each other outside a Shi'ite mosque in the southern city of Karachi.

Police said at least one person was killed and several others wounded in that attack.

Shi'ites are currently observing the holy month of Muharram.

Taliban spokesman Ahsanullah Ahsan claimed responsibility for the Rawalpindi and Karachi attacks, saying the Sunni fundamentalist movement is engaged in "a war of beliefs" against Shi'ites.

D-8 Leaders Gather

The violence came ahead of a leadership summit in Pakistan on November 22 of eight developing, predominantly Muslim nations known collectively as the Developing 8 (D-8).

The presidents of Iran, Turkey, Indonesia, and Nigeria, along with the leaders of Bangladesh and Malaysia, were expected to discuss ways of boosting trade and investment at the event, which Islamabad hoped would improve its standing.

President Asif Ali Zardari opened the leadership summit at the presidential palace in the Pakistani capital on November 22.

"The people of Pakistan stand with brothers and sisters across the D-8 world," Zardari told attendees. "In the pursuit for democracy, peace, and prosperity, it is only together that we can achieve our common goals, and together we shall."

Egyptian President Muhammad Morsi canceled his trip to Islamabad at the last moment, as he was concentrating on the implementation of the Gaza cease-fire that Egypt helped negotiate. Vice President Mahmud Mekki was attending the summit in his place.